NEW YORK-- Mitt Romney softened his tone toward teachers unions and highlighted his record as governor of Massachusetts at NBC News' Education Nation summit Tuesday in New York.

The Republican presidential nominee offered one of the most detailed glimpses of his education policy at the forum this morning, laying off his often brusque language toward unions and playing up parents' role in the educational success of their children.

Teachers' unions, long the villains in Romney's public remarks on education, received somewhat gentler handling from the GOP nominee today, who said he "understood" the unions had to look out for their members, and that they had a right to strike over grievances -- but that parents also had the prerogative to look out for their kids' educations.

"The teachers' union has every right to represent their members in the way they think is best for their members, but we have a every right to in fact say, 'No, this is what we want to do, which is in the best interest of our children,'" Romney said, before offering his prescription for improving the quality of teaching. "I believe the best interest of our children is to recognize that teaching is a profession, like your profession, like my profession, like lawyers, like doctors, and that the very best are more highly compensated and rewarded and measured."

President Obama delivers remarks at the Clinton Global Initiative annual meeting in New York City.

The former Massachusetts governor spoke and took questions on topics relating to education for 45 minutes here today as part of NBC News' Education Nation summit, and gave some of his most nuanced views yet on the issues at the heart of the effort to improve America's faltering public education system.

Romney also softened his tone, but did not change his argument, on the issue of class sizes, an issue on which he's battled teachers unions before, both in Massachusetts and on the campaign trail. Romney has called the fight for smaller class sizes a union-driven issue designed to spur the hiring of more teachers. He regularly cites a study authored by the consulting group McKinsey & Co. which shows class sizes, within a reasonable margin, are not a leading indicator of successful schools.

Today, Romney said his experience in Massachusetts taught him that class sizes "turned out to be a factor, but not a big one," to successful students, but continued to push for higher standards and pay for the best teachers, and for more parental involvement in education.

"The involvement of parents, particularly two parents, its an enormous advantage for the child," Romney said after retelling a story he heard from a teacher in Massachusetts who told him the way to tell if a student would succeed in school was whether or not their parents came to parent-teacher conferences with regularity.

Education has been one of the top issues for Romney outside 2012's dominant theme, the economy. The former Massachusetts governor often turns to the topic of education in speeches before minority audiences.

Romney held up several models for successful education reform; including his own tenure in Massachusetts, the reforms passed in Florida under Republican governor Jeb Bush, and the charter Harlem Children's Zone, some 100 blocks north of the site of today's event.

Romney even praised the current Secretary of Education Arne Duncan, mostly for his efforts to reward innovative schools and for opening options for more school choice, but stopped short of saying he would offer the Democrat a spot in his own cabinet.

"I'm not putting anybody on my cabinet right now, Brian," Romney laughed to moderator Brian Williams. "It's a little presumptuous of me, but just a little."

The Obama campaign wasn't laughing along.

“Mitt Romney’s education rhetoric today may have sounded nice, but it doesn’t square with his record or policies, which are informed by the mistaken belief that we can somehow improve our schools while cutting their budgets and laying off teachers," Obama campaign spokesperson Lis Smith said in a statement.